Valve-operating mechanism.



0. M. NACKER. VALVE OPERATING MECHANISM.

APPLICATION man APR. 14. m1.

1,254,840. j I Patented Jan. 29,1918.

Inf enter an IacXer awn S UNITED OFFICE.

OWEN M. HACKER, OF DETROIT, MICHIGAN, ASSIGNOR 0F ONE-HALF TO ALANSON 1'. I BRUSH, OF DETROIT, MICHIGAN, i 1

VALVE-OPERATING MECHANISM.

, Patented Jan. 29,

To all whom it may concern:

Bexit known that I, OWEN M. NACKER, a citizen of the United States of America, residin at Detroit, in the county of \Vayne and tate of Michigan, have invented certain new and useful Improvements in Valve- Operating Mechanism, of which the follow- Speciflcatlon of Letters Patent.

Application fllcd Apt-i1 i4, 1m. Serial No. 162,220.

ing is a specification, reference-being had' therein to the accompanying drawings.

The invention relates to valve-operating mechanisms in which puppetwalves are op- .erated by cams and tappets, as is usual in explosion engines. It is the object of the present invention to decrease the noise and at the same time to provide a larger range of clearance between the cam and tappet without objectionable noise than with constructions heretofore used, and tothis end the invention comprises the novel construction as hereinafter set forth. lathe-drawings:

Figure l'is a dia rammatic view, showing a puppet valve an' my improved actuating Furthermore in the ordinary course'o oporation the c earance will be increased until readjustment is made. a

With an ideal construction, in which all clearance is eliminated, at properly-formed cam will impart to the valve a simple harmonic movement in opening and closing, thereby avoiding any shock or noise. \Vhen, however, as is always true under practical conditions, there is a clearance, the point of enga ement and disengagement of the cam is 1W ere the angle is such as to impart a.

'high velocity tothe actuated member and consequently there is both noise and shock. A more gradual angle would avoidthis, but the necessity of performlng the complete opening and closing wit in agiven angle of rotation of the CfiIIt-Sha'i ,t requires a certain angular lift in t S lVith the present invention I have avoid ed the difficulties above described by the peculiar construction of the cam, in whicha,

certain portion for the opening and closing" of the valve is at such an angle as t-o lim1t the veloclty of movement in the actuated member so as to avoid objectionable "noise and shocks. This portion is sutliciently'extended to provide for the maximum clearance of the tappets, and consequentl will operate to limit the velocity in both initial lifting and final seating of the valve.

Various specific designs of cam mayx-be:

employed, according to the particular conditions under which they oierate, but the drawin s illustrate one speci 0 construction, in whic A representsthe cam, B' the valve and O the valve lifter. v 3, the lift of the cam is plotted, thederees of angular adjustment being upon the orizontal line and the lift of the cam in inches upon the vertical line.

As shown in Fig.

It will be observed that in the first ten degrees of angular moves;

m'ent of the cam from-its zero positionyor "from the points D to E,'Figs. land 2,

the angle 1s very gradualand will impart only a permissible velocity to the valve. Furthermore, the angle being the same,

throughout the ten degrees, it will make no difi'crence at what point the clearance'or back-lash is taken up, for the initial velocity will be the same. From the ten degree point' of angular adjustment the lifting angle is changed to a greater pitch requisite to complete the opening movement in. the required time, and a simi ar steep pitch'performs the greater portion. of the closin movement. There is, however, a final portion shown as including the last fifteen degrees of move ment, or between the points F and G, in

which the pitch is greatly reduced and 'is uniform to the zero point. Thus the velocity of the. valve will bechecked upon entering this final portion of the movement, so that it is immaterial at what point the seatiii takes place. A cam constructed as describe when incorporated in a valveslifting mecha n'ism, has in addition to the advantage of, eliminatingwear and noise the further ad-j/ vantage ',f permitting a greater degree of .clearanc or backlash in the t.appets 'without detrimentr; p In the diagram, Fig. 4, the velocity of he valve; is pjlotted, and it wlllbe noted t at velocity is constant fiQm the points I) to E and also from the points F to G. From the point E to the point; l-l there is a very rapid acceleration with a more gradual rctardin from the point, H to the point, I, then uni orm velocity Lo the point J, retarding from J to K and rapid acceleration from K to F.

What I claim as my invention is;--

1. The combination with a puppet-valve, of areciprocating member controlling the movement of said valve, and means for imparting to said member a substantially constant velocity during a portion of ils movement where said valve is adjacent to in: seatv 2. The (tombii'iation with n pup nabvalve, of a member coi'itrolling the IllClPlYlFllliUIl of said valve and, imparling l'herelo a variable velocity, the velocity of said melnlmr during the portirm of n'iovoment where said valve is ad'acent to its seat being sub stantially constant.

3. The combination with a puppetwalvc, of a cam controlling the roeiprnvation of said valve, said mm being fashioned to part to the valve a :substantially constant velocity during a, predetermined portion of its movemenl; a liaceni; to its seat.

&. The combination with mpuppet-valve, of a rotary it i for controlling the movement of said. Live-ma to impart, a eohetani-ially unifori'n velocity to the va dining a predc-Ecrmined angw la) movement of the i The comoin: ion with n, puppenvnlve, of a rotary for contro ling the move. ment of said valve, said com *0 g provided with a portion for effecting the requisite movement of the valve toward. and irom its '5 cam iieing fashioned seat during a predetermined singularmove-- n'ient 0f the cam said portion including a portion where the valve in adjacent to it's seal. of prodeterminedly-limitcd and sole stal'itiully-constant velocity, and also portion of variable velocity.

6: The combination with a puppet-valve of mechanism for opening and closing said valve provided with means for imparting substantially constant velocity to said valve when adjacent to its seat irrespective of variable amounts of backlash within said n'ieohanism.

T. The ccm'ibinat-ion with a puppet alve, of mechanism for opening and. closing said valve, provider] W'llll means For importing to the valve a IllilLlGlAiTlllillQllly'l llllUfl l substantially-nniform closing velocity irres 'iuxtive of variable amounts of back-lash Xlillih the actuating lncchuniem.

8. The ooinli mition with a puppebvalvm of mechanism for opening and closing said valve, provided with mean-: for im tnirti s to the valve a predeonmineellylimiterh sub stantiallvuniform velocity during its initial ooening movement irrespective of variations in {.he back-lash within said mechanism.

3. The combination with a pnp et-valve, of mechanism for opening and cloning said valve provided with means for imparting to the. "valve during: initial opening and final closing monuments thereof, a predetermin llfllllbil and enbslantially constant ve loonii:"irrespective of variations; in back-laeh wilz-hin e id mechanism;

in teemmony whereof 'I aiiix my signature.

EA. M HACK 

